When a person takes a bump of their favorite powder (usually meth, but can also be cocaine or china white), and some falls on their top lip or mustache. Severe cases can resemble a "milk mustache". Pronounced like "crank-in-stash".
"Bro, wipe off that krankenstache before your girl comes in the room."
"Sir, I'm going to need you to empty your pockets for me."
"Why?"
"You are wearing a krankenstache around in public; I feel you may be holding."